Multiple HD-SDI High-Speed Camera Capture

Hi,

I wasn't sure about where I should post this,
I'm interested in capturing up to 12 High-Speed camera streams over sdi over fiber boxes. But to capture, say a maximum of 12 cameras at the same time. So, I'm sure I'll have to look at the throughput of each stream and figure out how to handle that sort of dataflow through fibrechannel. But is this a really uncommon situation? Are there capture cards that support more than one channel of input?
Thanks